How to Install kubectl Linux Binary

The kubectl command is an essential part of Kubernetes, and is used to single handedly manage the entire cluster. It provides an interface for administrators to get information about their Kubernetes cluster, and manage the cluster through deploying applications and services, scaling systems, performing updates, and much more. On a Linux system, there are several ways to install the kubectl binary and to keep it up to date.

In this tutorial, we will cover several ways to install kubectl on all major Linux distributions. This will include installing the kubectl binary via direct download, or from various system package managers.

NOTE
Keep in mind that your kubectl version should correspond with the rest of your cluster. In other words, it is recommended to keep everything up to date, rather than updating kubectl on its own, or letting it fall out of date from the rest of the cluster. If the kubectl version does not match up with your cluster, it is likely to cause issues.

In this tutorial you will learn:

How to download and install the kubectl binary manually
How to install kubectl via apt package manager
How to install kubectl via dnf package manager
How to install kubectl with Snap universal package manager

Software Requirements and Linux Command Line Conventions
Category	Requirements, Conventions or Software Version Used
System	Any Linux distro
Software	Kubernetes, kubectl
Other	Privileged access to your Linux system as root or via the `sudo` command.
Conventions	# – requires given linux commands to be executed with root privileges either directly as a root user or by use of `sudo` command $ – requires given linux commands to be executed as a regular non-privileged user

Install kubectl Linux Binary

You have the option to download the kubectl Linux binary directly from the official Kubernetes site, and then keep it up to date manually. Another option is to use your system’s package manager to download kubectl and keep it updated that way. The latter option is probably easier for most users, but the former gives you more control. Use whichever method below that you find most appropriate.

Method 1: Manual installation of kubectl

First, let’s see how to download the kubectl binary and install it manually:

Use the following curl command to download the latest stable release of the kubectl Linux binary:

$ curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

Next, it is a good idea (but optional) to verify the checksum of the download. If your download resulted in a corrupt file for any reason, it could result in downtime or painstaking troubleshooting later on. Use these commands to download the checksum file and verify the binary:
```
$ curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"
$ echo "$(cat kubectl.sha256)  kubectl" | sha256sum --check
kubectl: OK
```

Now we can move on to installing kubectl:

$ sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl

You can check to see that you are now running the updated version of kubectl by executing:
```
$ kubectl version --client
```

Method 2: Using apt package manager

This method will work for Ubuntu Linux, Debian Linux, and any other distribution that uses the apt package manager.

Start off by installing the following prerequisite packages:

$ sudo apt update
$ sudo apt install -y ca-certificates curl apt-transport-https

Next, grab the Google Cloud public signing key with curl:

$ sudo curl -fsSLo /etc/apt/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg

Then, execute the following command to add the Kubernetes repository to your package manager:

$ echo "deb [signed-by=/etc/apt/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

Now we can use the ordinary apt install command to download kubectl:
```
$ sudo apt update
$ sudo apt install kubectl
```

Method 3: Using dnf package manager

This method will work for Fedora Linux, Red Hat Enterprise Linux, and any other Linux distribution that uses the dnf package manager.

First, use the following command to add the Kubernetes repository to your system:

$ cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-\$basearch
enabled=1
gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

Lastly, install the kubectl binary with your dnf package manager:
```
$ sudo dnf install kubectl
```

Method 4: Using snap package manager

Ubuntu comes with Snap installed by default, and many users also choose to install Snap on other distributions. It is a universal package manager, so the following command will work on any Linux distribution that already has Snap installed:

$ sudo snap install kubectl --classic

Closing Thoughts

In this tutorial, we saw how to install the kubectl binary on a Linux system. The kubectl tool allows administrators to control their cluster and keep an eye on all pertinent info. We saw several ways of how we can easily install the binary file and keep it up to date. Be sure to keep it updated alongside the same version number as your Kubernetes cluster to ensure that the command can continue communicating with the cluster as intended.